The present invention relates to a heat-exchanger plate for a plate-type heat exchanger with through-flow openings for fluid media, wherein these openings are arranged one next to the other in the plane of the plate and wherein the heat-exchanger plate is produced from a first material, in particular, steel or high-grade steel.
Furthermore, the present invention relates to a plate-type heat exchanger for fluid media with at least one inlet and at least one outlet for a first, in particular, slightly aggressive medium, with at least one inlet and at least one outlet for a second, aggressive medium, and with a number of heat-exchanger plates that are arranged in active fluid connection with the inlets and outlets in the plate-type heat exchanger.
Finally, the present invention relates to a method for the production of a heat-exchanger plate according to the invention.
Plate-type heat exchangers of the type noted above are known, for example, from EP 0 252 275 A2 and an example is shown in the accompanying FIG. 1.
FIG. 1 shows, in an exploded view, a known heat exchanger in which a package of essentially rectangular heat-exchanger plates 3 that are the same as each other and are rotated alternately relative to each other by 180° are mounted between end plates 1, 2. In the corner regions of the plates 3, through-flow openings 4-7 are formed by breaks that produce channels 9-12 when plate packages are pushed together, as shown by reference symbol 8, wherein two fluid media are fed alternately by means of these channels to the spaces formed between the plates 3 for mutual heat exchange.
Alternatively or additionally, the through-flow openings 4-7 could also be arranged in other plate regions, in particular, the plate longitudinal sides.
The spaces between the plates 3 for the fluid media are closed to the outside and in an alternating manner relative to the channels of one medium or the other medium by seals 13, so that one medium flows through one plate intermediate space and the other medium flows through the following plate intermediate space.
The four ports 14 attached to the end plate 2 on the outside are used for connections for the feeding and discharge of the two media. In addition, the heat-exchanger plates 3 between the end plates 1 and 2 are guided by bars engaging in recesses of the plates 3, wherein, of these bars, only the lower bar 15 is shown explicitly in FIG. 1. Alternatively, the connections could also be arranged on the other end plate 1.
The above functional description also applies to the present invention.
In the practical application of such plate-type heat exchangers or heat-exchanger plates, it can occasionally happen that one of the heat-exchanging media produces an especially aggressive, in particular, corrosive effect with respect to the plate material. In this case, the heat-exchanger plates must be produced from a corrosion-resistant material that withstands the aggressive properties of the medium. This, however, is associated with considerable added costs.
In this context, DE 83 10 039 U1 discloses the deposition of a full-surface, high-quality covering layer on at least one side of a heat-exchanger plate. In this way, the mentioned added costs are avoided only in part.